Fabrication of High-Surface-Area Graphene/Polyaniline Nanocomposites and Their Application in Supercapacitors

Abstract

Graphene/polyaniline (PANI) nanocomposites were prepared by reducing graphene oxide with hydrazine in the presence of different amounts of polyaniline nanoparticles. In situ cryo-transmission electron microscope (TEM) images of a graphene oxide (GO)/PANI solution revealed that the PANI nanoparticles were anchored on the surface of the GO sheets. During the reduction, the as-adsorbed PANI nanoparticles were sandwiched between layers of graphene sheets. These PANI nanoparticles acted as spacers to create gaps between neighboring graphene sheets, resulting in a higher surface area compared to pure graphene. Graphene/PANI nanocomposites exhibited the high specific surface area of 891 m2/g. Utilizing this composite material, a supercapacitor with a specific capacitance of 257 F/g at a current density of 0.1 A/g has been achieved.

Graphene-modified nanostructured vanadium pentoxide hybrids with extraordinary electrochemical performance for Li-ion batteries

“…1), while 10% graphene leads to a lower specific capacity, 278 mAh g À 1 , but much improved cycle stability. It is speculated that the lower graphene content may result in a better dispersion of the graphene sheets in the hydrogel of the V 2 O 5 , while the higher graphene content may lead to the restacking of the graphene sheets, as we observed in our previous work 27 . The thicker stacks of graphene (that is, 3-5 graphene sheets per stack) may hold the V 2 O 5 nanoribbons tighter and, thus, help maintain the structural integrity, consequently leading to a much better cycle life.…”

“…Then the GO dispersion was subjected to another centrifugation to remove the un-exfoliated GO. The resulting GO diluted solution could remain a very stable suspension without any precipitation for a few months 27 .…”

Recent advancements in metal organic framework based electrodes for supercapacitors

“…Furthermore, the low electrical conductivity increases irreversible capacitance and slows down the ion diffusion. Hence, conductive fillers like carbon materials and conductive polymers have been investigated to address these issues [24,25,86]. The composites can be prepared through a one-step method where the other materials participate in the reaction of preparing MOFs.…”

“…[17][18][19][20]. In general, the specific capacitance of these materials is higher than that of the carbon-based materials in EDLC supercapacitor electrodes, owing to the chemical adsorption and desorption of H + in acidic electrolyte or alkali metal cations in alkaline media [21][22][23][24][25]. However, there is debate on the classification of pseudocapacitive materials, because some exhibit distinct redox peaks in cyclic voltammetry (CV) loops as ionic battery materials do.…”

A Soft Template Method to Graphene Oxide Nanosheet/Polypyrrole Nanofibers Hybrid as Supercapacitor Electrode Material

“…One way to overcome this disadvantage is using a substrate, which serves as a support material for the electrochemical utilization of Ppy and also provides the path for electron transfer. As a good support substrate graphene oxide (GO) has attracted great interest recently [3,4]. Herein, we demonstrate the coating of polypyrrole (Ppy) nanofibers on GO and partially reduced graphene oxide (PRGO) using an in situ polymerization method with the help of soft template, aiming to achieve the 3D layered structure, which can enhance the mechanical strength of the composite and stabilize the polymers during the charge/discharge process.…”